The Silicon Tracking System of the CBM experiment at FAIR Anton Lymanets 1,2 for the CBM collaboration 14th Vienna Conference on Instrumentation February 15-19, 2016 Vienna University of Technology 1 GSI, Darmstadt, Germany 2 Institute for Nuclear Research, National Academy of Sciences, Ukraine
Facility for Antiproton and Ion Research GSI FAIR SIS 100 under construction existing facility SIS-100 protons: 30 GeV Au: 8 AGeV 2
QCD phase diagram СВМ Courtesy of K. Fukushima & T. Hatsuda nuclear matter formation at high baryon density and temperature models predict 1 st oder phase transition with formation of mixed and exotic phases existence of critical end-point 8 ρ 0 10 GeV/nucleon 3
Probing the dense fireball Au+Au collision at 10.7 GeV/nucleon as simulated in the UrQMD transport code p, Λ, Ξ +, Ω +, J/ψ Ξ -, Ω -, φ π, K, Λ,... ρ e + e -, μ + μ - resonance decays Leptonic and hadronic signals from all stages of nucleus-nucleus collisions Rare probes: multistrange hyperons, low mass vector mesons, charmonium, strange dibaryons, hypernuclei. 4
CВМ experiment Ring imaging Cherenkov detector Silicon Tracking System HADES: Dipole magnet Micro p+p, p+a Vertex A+A (low mult.) Time-of-flight detector Transition radiation detector Detector Online event selection on a computing farm Projectile spectator detector Muon detector Vertexing: MVD Tracking: STS, MUCH, TRD, ToF Particle ID: RICH, TRD, ToF Calorimetry: ECAL, PSD 5
Tracking challenge central Au+Au collision ~700 charged parbcles 6
Experimental requirements 10 5-10 7 Au+Au collisions per second. secondary vertex determinaion (σ 50 µm) track reconstrucion from hadron and lepton probes fast and radiaion tolerant detectors self-triggering front-end electronics fast data acquisiion system + online event selecion on a compuing farm 4D track reconstrucion 7
Online data flow First-level Event Selector 8
Feasibility studies at SIS-100 Operation scenario: Au+Au, С+С at 4, 6, 8, 10 GeV/nucleon Example: 10 6 central events, interaction rate 100 khz 1 MHz Charmed mesons: D ± Kππ Cascade hyperons 30 GeV p+c Au+Au, 8 GeV/nucleon 9
CBM Micro Vertex Detector Ultra-thin: CVD diamond, TPG Sensors: CMOS MAPS Radiation hard, Thinned to 50 µm, < 150 mw/cm 2, spatial resol. < 5 µm, R/O several 10 µs/frame MVD demonstrator Prototyping & test beam: MVD prototype PRESTO Customized FEE & DAQ: TRB-based RVC foam 10
Silicon Tracking System STS beam 2.5 25 1 m target 8 tracking stations in the magnet aperture double-sided silicon microstrip detectors Acceptance: 2.5 <! < 25 Active area: 4 m 2 11
STS integration concept X/X 0, % 1 m 8 tracking stations mechanical unit ladder material budget for station 8 896 detector modules including: 1220 double-sided microstrip sensors ~ 1.8M readout channels ~ 16 000 readout chips ~ 16 000 ultra-thin readout cable stacks 12
Detector module concept 896 modules required 4-5 modules per ladder Modules comprises: sensor analog mirocables front-end board 13
Silicon microstrip sensors double-sided 1024 channels per side 58 µm pitch 300 µm thick stereo angle 7.5 (р-side) dimensions: 6 2 cm 2, 6 4 cm 2, 6 6 cm 2, 6 12 cm 2 2 nd metallization to interconnect short corner strips 14
Silicon microstrip sensors two daisy-chained sensors 6 12 cm 2 sensor design with readout pads in the middle of the sensor (in production by Hamamatsu) 15
Microcables meshed spacer signal layer: 64 Al lines of 116 µm pitch, 10 µm thick on 14 µm polyimide, lengths up to 55 cm Material budget: 0.228 X0 (equivalent to 213 µm Si) 16
STS-XYTER ASIC STS-XYTER ASIC CSA + PSC SLOW SHAPER FAST SHAPER FAST DISCRIMINATOR 5-BIT FLASH ADC READOUT/TEST CONTROL LOGIC data driven architecture fast branch: time-stamp slow branch: signal digitization double-threshold discrimination: time stamp is vetoed if ADC produced no signal channels 128, polarity +/- t s = 30 ns noise ADC range 1000 e at 30 pf load 16 fc, 5 bit LSB veto r/o logic CBM-NET (v1.0 ) GBT (V2.0) clock power timestamp out interface 250 MHz < 10 mw/channel < 5 ns resolution 4(5) 500 Mbit/s LVDS t s = 80 ns 17
Detector module assembly TAB bonding of microcables to ASICs and sensors 18
Current engineering studies cooling TRACI XL: 1 kw cooling prototype Cooling plate cabling Front-end Electronics Boards Read-out Boards, Power Boards bi-phase CO 2 cooling system STS electronics total: 42 kw FEB stack 200 W cooling plate with integrated channels 19
STS performance simulation Track reconstruction efficiency Momentum resolution realistic detector model CbmRoot simulation framework Cellular Automaton track finder Kalman Filter track fitting 20
Summary STS system concept has been presented Detailed geometry has been assessed in simulations: performance OK Current activity is module assembly and system integration Full-size module mockup has been produced Production readiness by the end of 2016 21
BACKUP 22
Radiation environment FLUKA calculation of non-ionizing dose for 35 AGeV Au+Au collisions at SIS300 and the CBM experiment in muon configuration. 607th Heraeus Seminar, Bad Honnef, Feb. 2016 J. Heuser - Silicon trackers for heavy-ion physics 23